The present invention relates to trouble lights and, more particularly, to an improved trouble light and shield therefor in which the risk of being burned through contact therewith is minimized.
Trouble lights are a common device used by service personnel and many automobile owners to illuminate an area, such as, for example, under an automobile, where inadequate lighting conditions hinder the ability to work in such an area. In the past, trouble lights typically consisted of a switch and socket assembly, a light bulb secured within the socket, and a housing combining a sheet metal reflector and a wire guard. These lights utilize the reflector positioned on one side of the bulb to reflect the light towards the work area. The wire guard portion of the housing was used to prevent inadvertent contact with the bulb which would cause burns and possibly break the bulb. Also, the reflector in these lights typically abutted the wire guard and provided one or more points of contact between the two and transferred heat to the wire guard. A problem associated with this type of light stems from the fact that the light bulbs utilized therein must provide sufficient illumination on the work area. The bulbs which fulfill this need develop a considerable amount of heat. Since the bulb is positioned in close proximity to the reflector portion of the housing, the temperature of the reflector portion can rise due to radiation and contact between the reflector and wire guards and produce a painful burn, even after only a short period of use. In addition, trouble lights are often used in applications where the work space is cramped. Therefore, it is desirable to construct the housing assembly as small as possible so that the light can be inserted where desired. Decreasing the size of the housing, however, moves the reflector portion closer to the light bulb and also moves the reflector into contact with the guard and thus increases the temperature of the reflector.
Various types of trouble lights have been designed in an effort to prevent burns caused by the reflector. One is disclosed in U.S. Pat. No. 3,108,752 in which a trouble light having a housing made from a wire guard and a sheet metal shield is disclosed. A reflector having ventilating slots therein is concentrically mounted to the shield between the shield and the bulb by a pair of rivets. While such a construction initially insulates the shield, after prolonged use, both the reflector and the shield attain high temperatures due to the minimal circulation of air between the reflector and the shield.
U.S. Pat. No. 4,328,535 describes a trouble light having a thermal insulating cloth pad which is positioned on the exterior surface of the reflector. This insulating pad may become snagged in a congested work area and become separated from the reflector and thus require the user to occasionally reposition it. In addition, because the pad is made from cloth, it will likely absorb moisture and/or grease and/or oil whereby it will readily conduct heat through the pad, or even worse, become a fire hazard.
Fluorescent bulbs have also been proposed to replace the typical incandescent bulb because of their lower operating temperatures. However, fluorescent bulbs are substantially more expensive than a comparable incandescent bulb thus making the fluorescent-type trouble lights cost prohibitive for many purchasers.
The trouble light of the present invention overcomes the aforementioned shortcomings by utilizing a wire guard assembly which completely encircles the bulb and reflector. The reflector is positioned substantially adjacent the bulb. An air gap is provided between the reflector and the wire guard and contact between the reflector and guard assembly is prevented to effectively prevent substantial heat transfer between the reflector and the wire guard. Any minimal heat transfer which may occur is further minimized by coating the wire guard with a thermal and electrical insulator. The wire guard has a plurality of wires which are radically spaced apart and prevent inadvertent contact by the user with the reflector. The air gap between the wires and reflector permits air to freely pass over the reflector and prevent heat transfer to the guard such that the guard maintains a relatively cool temperature which a user may contact without being burned.
Accordingly, it is a general object of the present invention to provide an improved trouble light.
Another object of the present invention is to provide a trouble light having a predetermined distance and an air gap between the reflector and the guard assembly to eliminate heat transfer to the guard assembly.
Another object of the present invention is to provide a trouble light in which the wire guard assembly surrounding the light bulb is coated with a thermal insulator.
A further object of the present invention is to provide a trouble light in which the wire guard surrounding the light bulb is coated with a thermal and electrical insulator.
A still further object of the present invention is to provide a trouble light in which the light bulb enclosed within the housing is readily accessible.
Yet another object of the present invention into provide a trouble light shield with positioning means to maintain the light reflector a predetermined distance from the guard assembly and to prevent relative movement and contact between the two.
These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.